I hadn't heard of this problem on other 8's, but lately my cabin HVAC fan/blower is making more and more noise, like a ticking.

As for the sound, think back to the sound the Wheel of Fortune wheel made as the little ticker would hit it the pegs, after a burly lumberjack just spun the wheel.

Ticking rate increase as you turn know to increase blower speed, does not seem to be affecting air flow though.

 

Possibly a bit of a leaf or piece of paper got sucked in and is rubbing on the fan.

 

As I cited in another thread on air flow, most often debris on the fan blades is the noise culprit. As Nubo cites possibly a leaf or paper fragment.

Think playing card in bicycle spokes.